Artículos de revistas
Extrinsic functions of lectin domains in O-N-acetylgalactosamine glycan biosynthesis
Fecha
2016-12Registro en:
Lorenz, Virginia; Ditamo, Yanina; Cejas, Romina Beatríz; Carrizo Garcia, Maria Elena; Bennett, Eric P.; et al.; Extrinsic functions of lectin domains in O-N-acetylgalactosamine glycan biosynthesis; American Society for Biochemistry and Molecular Biology; Journal of Biological Chemistry (online); 291; 49; 12-2016; 25339-25350
0021-9258
1083-351X
CONICET Digital
CONICET
Autor
Lorenz, Virginia
Ditamo, Yanina
Cejas, Romina Beatríz
Carrizo Garcia, Maria Elena
Bennett, Eric P.
Clausen, Henrik
Nores, Gustavo Alejandro
Irazoqui, Fernando Jose
Resumen
Glycan biosynthesis occurs mainly in Golgi. Molecular organization and functional regulation of this process are not well understood. We evaluated the extrinsic effect of lectin domains (β-trefoil fold) of polypeptide GalNAc-transferases (ppGalNAc-Ts) on catalytic activity of glycosyltransferases during O-GalNAc glycan biosynthesis. The presence of lectin domain T3lec or T4lec during ppGalNAc-T2 and ppGalNAc-T3 catalytic reaction had a clear inhibitory effect on GalNAc-T activity. Interaction of T3lec or T4lec with ppGalNAc-T2 catalytic domain was not mediated by carbohydrate. T3lec, but not T2lec and T4lec, had a clear activating effect on Drosophila melanogaster core 1 galactosyltransferase enzyme activity and a predominant inhibitory effect on in vivo human core 1 glycan biosynthesis. The regulatory role of the β-trefoil fold of ppGalNAc-Ts in enzymatic activity of glycosyltransferases involved in the O-glycan biosynthesis pathway, described here for the first time, helps clarify the mechanism of biosynthesis of complex biopolymers (such as glycans) that is not template-driven.